Synchronizing multiple nx500 cam

[gius19]

Hi, I am new to this repository. I would like to synchronize a set of nx500 cam to take panoramic 360 degree pictures. No experience in programming. I have a few questions: 1) using nx500_nx1_modding the camera can shoot photo with electronic shutter at maximum resolution in photo mode? 2) would it be possible using nx500_nx1_modding to (wire)connect multiple nx500 cam to have all to shoot (using electronic shutter) at the same time with a tolerance of 1ms? For example: I send a (wired) signal to all the cams at the same time and each cam starts the read out process with a maximum delay of 1ms?

Thank you very much.

Giuseppe Porciani

[ottokiksmaler]

Hi

1) Yes, full resolution, SRW or JPEG - just in single mode (all other modes will use mechanical shutter) 2) I'm sceptical that you could synchronize down to less than 1ms between cameras (for any non-industrial camera, I know even a lot of commercial 360 cameras have small delays between individual cameras). You could try and report back as I'm interested myself.

I'm not sure why you would need such a small delay? In order to have any chance, you would need to use fully manual exposure, no AF, no AWB, no DR mode, etc - making the camera as "dumb" as possible.

Still, 1ms is very very short time. You have to take into account that the sensor needs to be cleared before exposure and even electronic first curtain will take several ms (even on the fastest general purpose sensors). Then the readout will take ~30ms for electronic shutter to actually read out the sensor (the fastest camera is Sony a9 with ~6ms).

[gius19]

ottokiksmaler ha scritto:

Hi

1. Yes, full resolution, SRW or JPEG - just in single mode (all other modes will use mechanical shutter)
2. I'm sceptical that you could synchronize down to less than 1ms between cameras (for any non-industrial camera, I know even a lot of commercial 360 cameras have small delays between individual cameras). You could try and report back as I'm interested myself.

I'm not sure why you would need such a small delay? In order to have any chance, you would need to use fully manual exposure, no AF, no AWB, no DR mode, etc - making the camera as "dumb" as possible.

Still, 1ms is very very short time. You have to take into account that the sensor needs to be cleared before exposure and even electronic first curtain will take several ms (even on the fastest general purpose sensors). Then the readout will take ~30ms for electronic shutter to actually read out the sensor (the fastest camera is Sony a9 with ~6ms).

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Hi,

Thank you very much for your reply. I would need a good synchronization because in many scenes there are moving objects and a delay in taking the pictures means a different position of the moving object in the overlapping area of two images which implies stitching problems. It is like to increment the parallax error. I will use the cameras in manual mode; fixed aperture and focus. In this way perhaps it is possible to connect the remote release of each camera to send a signal to all the cam at the same time. Then we have the lag between cameras. I read (http://breezesys.com/MultiCamera/release.htm) that with this configuration it would be possible to have all the cams to shoot at the same time with a delay of 1, 2, 3 ms. Not sure to understand correctly.

I send a signal to shoot at the same time to all cams, each cam start its sensor (after a delay): I am wondering if there is a way via your software, to stop the beginning of read out in each sensor until "all the sensors are ready" and then beginning the read out process. I am tottally incompetent in electronics; sorry if all that is meaningless.

I would also have another question: when you say the camera works with electronic shutter do you mean "fully electronic shutter" or do you mean the camera uses the electronic first courtain?

Thank you very much.

Giuseppe

[ottokiksmaler]

Ok, I misunderstood your question, I thought you needed 1ms delay from you pressing the button to the end of the exposure. I cannot test as I have just one camera but the delay between cameras should be very short if you use the cameras as I described. Do note that reading out of the sensor takes ~30ms so fast moving objects will be skewed (read about the rolling shutter). This is a limitation of all but the most expensive (industrial) sensors (that use global shutter). If you have problem with that, you will have to use the mechanical shutter.

There is no way I know of to pause the reading out of the sensor. Without the hack NX500 can use electronic first curtain, with the hack it can use fully electronic shutter (no movement, no sound - do note that if you use NX lenses at some smaller apertures there is both some delay to stop down and sound of aperture closing down, if using full manual lenses there is nothing).

[gius19]

Thank you very much for useful suggestions and hints. I am considering using Samsung nx500 just because I found your software but I do not have one yet. I know there is a software "SDM" for Canon point and shot cameras which may obtain synchronisation of multiple cameras with a very short delay, about 1/2000s or less (for some cameras maybe 1/8000s). Unfortunately these cameras use a mechanical shutter. The cameras are triggered by a wired switch. As far as I know these cameras can not operate in manual control (at least for focusing). Because of the short delay I thought the software would have some kind of control over the readout process to "co-ordinate" all the sensors. If not, that would mean the cameras' lag when triggered is very, very short. If this is the case I hope that Samsung nx500 behaviour would be similar.

----- Original Message ----- From: ottokiksmaler To: ottokiksmaler/nx500_nx1_modding Cc: gius19 ; Author Sent: Thursday, February 14, 2019 6:41 AM Subject: Re: [ottokiksmaler/nx500_nx1_modding] Synchronizing multiple nx500 cam (#107)

Ok, I misunderstood your question, I thought you needed 1ms delay from you pressing the button to the end of the exposure. I cannot test as I have just one camera but the delay between cameras should be very short if you use the cameras as I described. Do note that reading out of the sensor takes ~30ms so fast moving objects will be skewed (read about the rolling shutter). This is a limitation of all but the most expensive (industrial) sensors (that use global shutter). If you have problem with that, you will have to use the mechanical shutter.

There is no way I know of to pause the reading out of the sensor. Without the hack NX500 can use electronic first curtain, with the hack it can use fully electronic shutter (no movement, no sound - do note that if you use NX lenses at some smaller apertures there is both some delay to stop down and sound of aperture closing down, if using full manual lenses there is nothing).

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[ottokiksmaler]

If you are planning to create 360 shots I guess you will be using 180 fisheye lens? In that case, get a Canon and Samyang (rokinon, bower, opteka - all the same) 8mm f/3.5 fisheye lens. It's fully manual - manual focus, manual aperture, just switch the camera to M mode and set the ISO and shutter speed.

[gius19]

Thank you. I have already a samyamg 8mm for a sony nex. I think I will buy for samsung nx if I decide to set a rig with these cameras and your software to use electronic shutter. ----- Original Message ----- From: ottokiksmaler To: ottokiksmaler/nx500_nx1_modding Cc: gius19 ; Author Sent: Thursday, February 14, 2019 1:13 PM Subject: Re: [ottokiksmaler/nx500_nx1_modding] Synchronizing multiple nx500 cam (#107)

If you are planning to create 360 shots I guess you will be using 180 fisheye lens? In that case, get a Canon and Samyang (rokinon, bower, opteka - all the same) 8mm f/3.5 fisheye lens. It's fully manual - manual focus, manual aperture, just switch the camera to M mode and set the ISO.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[gius19]

I would like to buy 2 Samsung n500 to test the software for full electronic shutter use and to try to synchronize the cams but I still have doubts about the possibility to synchronize the shutters by simply connecting the cams via a wired remote shutter.

For some Canon cameras a software (SDM) is available which, when installed, can achieve shutter synchronization with a delay of about 1/200 s or less between cams connected by way of a wired switch. No idea how it might work. I was wondering if you could add a similar multiple cams synchronization in your software for Samsung nx500.

Thank you.

Giuseppe Porciani

[gius19]

Sorry I mistyped : SDM for Canon cameras may synchronize the shutter with a delay of 1/2000s or less.... Thank you

[ottokiksmaler]

I would strongly suggest that you use already working solution available for Canon cameras.

I don't have two NX500 cameras to experiment with and cannot develop a sync solution without at least two cameras. Even if I had multiple devices there is no guarantee that I would be able to do it.